Electronic controls are widely used in trucks for a variety of applications. For example, sophisticated electronic control devices including programmed microprocessors are commonly used to control antilock brake systems, powertrains, and transmissions. These electronic devices have provided new functionality, such as the antilock brake systems, and have improved performance of existing components. While electronics have significantly improved functionality and performance, they have also increased the complexity of trucks.
As the use of electronic systems in trucks has grown, a number of electronic control devices or units have been developed for specific applications. For example, engine manufacturers have designed special purpose computers for controlling and monitoring engine performance. Brake manufacturers have designed electronic control devices to control sophisticated antilock brake system. Still other manufacturers have developed control units for air suspension systems. Since each of these devices are designed for different purposes, they are not typically designed to work together or to communicate with each other.
With the increasing sophistication of truck electronics, a need arose to provide a means for communicating data from the disparate electronic control systems on board the vehicle. Two standards developed for communication between electronic devices in vehicles are SAE (Society of Automotive Engineers) J1708 and J1587. SAE J1708 defines the requirements of the hardware and basic protocol for communicating data between electronic control systems or units. SAE J1587 provides a common format for messages and data communicated between the electronic control systems.
Despite the adoption of these standards by many in the industry, they alone do not solve many problems associated with installing and servicing electronic devices on today's trucks. For example, the standards do not provide any mechanism for determining which components are installed, or for determining whether the installed components are compatible.
One problem associated with these electronic systems is ensuring that they function properly and that they are compatible. The truck manufacturer can build and test the electronics to make sure that they are operational. However, it is very common for others to modify the truck with after-market electronic parts which do not operate properly or are incompatible with other components. In these circumstances, it is likely that the truck will have a number of electronic components that have never been tested by the truck manufacturer.
The lack of proper installation of electronic controls is a major problem for truck manufactures and service providers. Studies show that in excess of 50% of electronic components returned are found to operate properly. As such, considerable time and money is wasted in addressing problems that could have been avoided had the electronics been installed and configured properly.
Another problem associated with electronic devices installed on trucks is that they can exhibit erroneous behavior if not properly reset before delivery to the customer. During the truck assembly process, an electronic control unit may be used in a manner that makes it think there is a problem or a "fault." For instance, it is common for an assembler to power up an electronic subsystem before installing it in a vehicle. In these circumstances, the subsystem usually generates a number of faults because all of its sensors are not yet installed and calibrated.
The faults generated during the assembly process can be a serious problem for customers and service technicians because they make it appear as if there are problems with the vehicle. It is imperative, therefore, that all of the faults be cleared from the truck's electronics at the truck manufacturing plant. This is often time consuming because it may involve entering a series of commands at a keypad just to reset or re-program a single device. In other cases, it may require a technician to connect a hand held diagnostic tool or computer to an electronic subsystem to separately reset electronic subsystems in the truck. Often the diagnostic tool or computer require considerable reconfiguration to take advantage of proprietary software from the vendor of the electronic subsystem.